The present invention relates to a data-providing system, a transmission server, a data terminal apparatus and a data-providing method, each designed to achieve streaming transmission of multimedia contents, such as dynamic-picture data, still-picture data, audio data, computer data and the like, through Internet, a cable television network, a personal-computer communication network, a large-scale LAN or a data communication network such as radio communication network or a wire broadcasting network.
In a data communication network such as Internet, streaming transmission of data is performed, enabling users to select and obtain at their terminals any on-demand programs they want.
The on-demand programs are stored in the transmission center that transmits or broadcasts the on-demand programs. Among the programs the transmission center stores are:    1. Year-end movies and new-year movies, each containing commercials for Christmas sales    2. Year-end movies and new-year movies, each containing commercials for new-year sales    3. Year-end movies and new-year movies to be broadcast in night hours, each containing commercials for commercials
Upon receipt of a demand from any user, the transmission center selects and transmits the program (e.g., a movie of any of the categories 1 to 3 described above) the user wants to enjoy. Different prices are set to the on-demand programs and costs are distributed to them.
Jpn. Pat. Appln. KOKAI Publication No. 9-18851 discloses a system in which video programs are distributed via a network, any program is selected at a terminal, and a user can select a program containing commercials or a program containing no commercials at his terminal.
In the existing on-demand broadcasting, the user can selects a plurality of programs at a time but cannot select one of the versions, if available, of the same program.
As the Internet technology advances, various contents prepared to meet the users' tastes are distributed in increasing numbers. People now wish to obtain data customized to their tastes, rather than the information presented by mass media. If data customized to the different tastes of the users is prepared, it will be an extremely amount of data. To store a large amount of data, the transmission center needs to have a large storage capacity. In addition, it takes much time and labor to edit programs to adapt them to the users' tastes that keep changing.
In the on-demand broadcasting practiced hitherto, one price is set to a combination of programs and a cost is distributed thereto. If the combination of programs is changed immediately before the programs are transmitted, it becomes difficult to determine what should be the price of the new combination and how the cost should be distributed thereto. Further, the storage capacity the transmission center must have for the library of programs grows considerably large. The transmission center needs to have an extremely large storage capacity, particularly if there is prepared a plurality of various parts that are to be inserted into programs. In this case, price-setting and cost-distribution are required for each of these program parts.